@Nathan: Unfortunately I have to hold my tongue much more than I like as the work I do is freelance and my work world and personal world intertwine too much in my social media world and while I don't mind taking the social hit when it comes to these sort of situations, it would threaten my livelihood to speak my mind too fully.

Most of my "evangelism" tends to be through positive promotion of science and logic. I also tend to pounce on pseudoscience claims and urban legends. I think this approach it tends to work a bit better anyway, at least in my circles, as bashing stupidity like this directly tends to leave you ignored, where chipping away one minor myth at a time can (hopefully) guide people toward logic.

Your evangelical side will probably yield faster results than direct attacks against their warped perception of reality that gawd has something to do with EVERYTHING. It is tough though not to pierce the tissues of one's tongue when dealing with these sorts.